In transmission systems, the number of users served by a station and an amount of data communicated have been increasing recently along with widespread utilization of smartphones and the like and diversification of services using the Internet, for example. A transmission apparatus to be used in a transmission system simultaneously processes various kinds of data such as voice data whose delay is not acceptable and mail data whose delay is acceptable to some extent. Accordingly, the transmission apparatus identifies priorities of data according to data types and executes data processing according to the priorities.
For example, the transmission apparatus realizes high-speed scheduling with queue selection while accommodating many users and identifying data priorities of variable length packets. As such a high-speed scheduling method, a per-packet round robin (RR) scheme, for example, is employed.
However, in a per-packet queue selection method such as the RR scheme, if a queue selection time is longer than a packet processing time, a time gap occurs between packets outputted from a selected queue. This causes deterioration in packet transmission performances for efficiently transmitting packets. Accordingly, the per-packet queue selection method adopts a mechanism to select a queue within a processing time for the shortest packet among multiple packets.
Japanese Laid-open Patent Publication No. 2002-300577, Japanese Laid-open Patent Publication No. 11-298523, and Japanese Laid-open Patent Publication No. 2009-135810 are examples of the related art.